Mission Highly Improbable Plants

I'm building out a new bed (about 16 x 4), part shade until noon, then bright sun until early evening. It must be x-xeric, and tolerant of occasional temperature extremes in winter (highs of 60 and lows of -10 in winter, 100 and 45 respectively in summer).

The objective is to collect some HIghly Improbable plants -- blue does not exist in roses, black is almost nonexistent in most flowering species, etc.

I started out with the inspiration of "The Black Tulip" (Dumas), and put in a bunch of "Queen of the NIght" black tulips, accented by deep scarlet (nearly black) pansies, followed by "Superstition" iris and a deep crimson/black centered poppy.

For the Early June - August period I have "Wild Blue Yonder" grandiflora roses, Green Wizard Rudbeckia, and black mondo grass.

I need some more summer flowering plants, in improbable colors. Oddly shaped or contorted flowers (ex: ChimChiminee Rudbeckia) are fine also, with emphasis on darker tones.

This should be fun!